old microcode listings
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From: "Peter "Firefly" Lund" on 30 Dec 2006 20:27 On Fri, 29 Dec 2006, ChrisQuayle wrote: > If you could make do with more general pdp11 stuff, I think the early > pdp11/05 field maintenance print set had listings of the microcode prom > contents. Hmmm, might be worth a shot. > The T11 was the micro used on the Falcon embedded qbus board right ? - spent Yes, and in the Paperboy video game. > a couple of years writing macro 11 for that board and may still have the ug > somewhere, though not sure if it includes microcode listings. bitsavers.org > may be a good place to start for any of the older mini info. Nope, it doesn't (I got my copy from bitsavers). > So what's so interesting about the T11 ?. A more modern embedded equivalent That it's a very tight PDP-11 implementation, the only single-chip PDP-11 Digital ever made. According to: http://simh.trailing-edge.com/semi/t11.html it 17,000 transistor "sites", which according to another source I found translated to about 10,000 actual transistors. This includes registers and microcode. > would be the Texas msp430. The msp is a risc design under the skin, but the > registers, instruction set and addressing modes look like it's been cribbed > almost direct from the pdp architectural model. Dejavu indeed... Noted, thanks. -Peter
From: ChrisQuayle on 31 Dec 2006 07:45 Peter "Firefly" Lund wrote: > >> If you could make do with more general pdp11 stuff, I think the early >> pdp11/05 field maintenance print set had listings of the microcode >> prom contents. > > > Hmmm, might be worth a shot. > > -Peter On a more general note, so much stuff from science is becoming lost, difficult to find and/or expensive to access. The T11 microcode is just one example. Were all the docs just binned when dec or later owners closed the labs, or has some individual or organisation somewhere still got the docs ?. Having a good historical perpective on a subject can save a lot of time in terms of wheel reinvention. The problem is I guess that companies like dec were so prolific in terms of innovation that it may be impossible to store, let alone catalog and digitise all of it. As someone who finds the history of science more than just interesting, I think we should be taking far better care of our scientific heritage and making it more readily available at low cost or free for researchers. I know there are many organisations that digitise and make it available, but it can get quite expensive if you need several papers and often you need to read a paper to find out if it's relevant. One excellent free sources is the Nasa Tech reports server - has stuff dating back to the 60's, a period when there was a real push in terms of research and innovation... Chris
From: "Peter "Firefly" Lund" on 31 Dec 2006 14:27 On Sun, 31 Dec 2006, Peter "Firefly" Lund wrote: >> would be the Texas msp430. The msp is a risc design under the skin, but >> the registers, instruction set and addressing modes look like it's been >> cribbed almost direct from the pdp architectural model. Dejavu indeed... > > Noted, thanks. It does look a bit like a PDP-11 with more registers and fewer addressing modes and with both more regularity in the registers (even the flags are in a general-purpose register vs. just the PC and SP on the PDP-11) and less regularity (R3 is not there -- if used as source it will generate one of a few constants based on the addressing mode! Likewise, R2, the flags register, will generate constants in some addressing modes). -Peter
From: kenney on 1 Jan 2007 05:59 In article <LhOlh.7019$Wy6.535(a)newsfe1-win.ntli.net>, nospam(a)devnul.co.uk (ChrisQuayle) wrote: > On a more general note, so much stuff from science is > becoming lost, difficult to find and/or expensive to access. It is not just science that applies to. About the only organisations that attempt to keep all documents as a matter of record are Governments. In industrial history (a hobby) you are largely dependent on secondary sources written before production and technical records were lost or thrown away. Ken Young
From: ChrisQuayle on 3 Jan 2007 11:11
Peter "Firefly" Lund wrote: > > It does look a bit like a PDP-11 with more registers and fewer > addressing modes and with both more regularity in the registers (even > the flags are in a general-purpose register vs. just the PC and SP on > the PDP-11) and less regularity (R3 is not there -- if used as source it > will generate one of a few constants based on the addressing mode! > Likewise, R2, the flags register, will generate constants in some > addressing modes). > > -Peter Agreed, there is quite a bit of variance, but it's easy to see which architecture they were inspired by. Not bad for a system that was designed in the late 60's. I think the very first pdp used hard wired logic, instead of microcode, but by the 11/05, the boards were full of bipolar proms and (iirc) Texas 74181 bit slice. The saying used to be about the pdp that any addressing mode works with any instruction and / or register, so long as it sounds sensible and it is more or less true as well. After programming various intel and other micros in assembler, the pdp seemed like pure luxury :-)... Chris |